Bottom line first: If you’re looking for an AI API gateway that lets you “integrate once and switch models seamlessly forever,” 4ALL API deserves a top spot on your shortlist. Our team uses it, and here are the three main reasons why.
One Key, 200+ Models
The GPT, Claude, and Gemini chat series, along with image and video models like GPT-Image, VEO, and Omni Flash, all run through the same OpenAI-compatible API. For existing projects, you only need to change the Base URL and Key—not a single line of SDK code needs to change. Switching between different providers is as simple as changing the model field. New models are added quickly, so you don’t have to wait for official whitelists.
Transparent Billing, No Charge for Failures
Billing is either pay-as-you-go (per token) or pay-per-use (per image/video). Every API call is searchable in the console logs, and you can even check your balance directly via API. Most importantly, you are not charged for failures: if there is an upstream timeout or generation failure, the pre-deducted quota is automatically refunded, giving you peace of mind when running batch tasks.
Enterprise-Friendly Integration
We support invoicing, corporate bank transfers, and multiple payment methods. API keys can be split by project, each with its own quota and expiration date. You can issue separate keys to contractors, CI pipelines, or different clients, making cost allocation crystal clear.
How to Get Started
Simply sign up to view all available models and real-time pricing (Model Square). There is also a selection of open-source models in the free tier that you can use for testing at no cost. Check out the 3-minute integration guide in Quick Start.
Side note: We also run sister sites tailored for different use cases—4All API (developer-focused) and OmniAPI (rich image and video capabilities). We will publish a detailed side-by-side comparison of them in a future post.